ZWO ASI 224 MC All Sky Cam - Hot Pixels/Settings ?

[Spaced Out]

Hi All

I’ve just bought some gubbins to make a DIY all sky cam, hoping to knock something up this week.

I’ve got a ZWO ASI 224 MC for this little project and I used it for the first time tonight just to test it out. I’ve only really used DSLRs before and never used sharpcap either so not a clue what I was doing with it all tbh !

Anyway, this is my first test image from my back garden. Thin cloud, perhaps focus isn’t perfect but I was happy that I got some stars and even a bit of Milky Way in there.

I do have 2 questions.....

1 - I was quite shocked at what appears to be LOTS of hot pixels (red and blue dots). I assume these are hot pixels I am seeing here and not bright stars ? The colours seem too bright but I can only see one red dot in the dark corners of the image ? If they are hot pixels, is this normal for this sort of camera ? It was a 30 second exposure with gain set to around 320.

2 – What is the best way to achieve perfect focus ? I am using the Arecont 1.55mm lens which is really fiddly (it shifts when you lock the focus), especially outside in the dark with cold fingers ! I am just wondering whether it’s worth trying to set up the focus in the daytime which should be easier, and if anyone knows the infinity focus distance for this particular lens ?

Thanks for any advice you can offer !

Edited January 15, 2020 by Spaced Out

[Spaced Out]

OK, no replies ! Here's an update then.

I've dibbled on with this and started using AllSkEye software to take some more test shots to try and find the best settings before running it for real. I've used a hot pixel map in the software too and I have discovered that those red dots in my first image are actually stars. It was cloudy last night but another test shot revealed no hot pixels where there was cloud, but the small areas of clear sky has the same stars including some orange looking ones !

I have also improved the focus to get tighter stars, I did this by focusing in the daytime on a house chimney over 30m away, seemed to do the trick.

Next job is to see if I can improve the white balance a bit and then learn more about the AllSkEye software which looks really useful. 👍

[Altocumulus]

Interesting. I have a similarly noisy sensor on my 120MC.

A recent image....A lot of my dots don't move :D. Even as low as 5 seconds I seem plagued with the little pests. Gain, I have as low as 20 to try and get rid of them...

Many of my images have vertical lines, too. Perhaps I need to improve my focus, but I'm close to throwing this camera in the nearest bin!

p.s. I'm also using AllSkEye software - but the bad pixel mapping is befuddling me!

 

 

 

 

Edited February 21, 2020 by Altocumulus

[happy-kat]

Hope you have both got further on with this.

The hot pixel map tool I'm using a balance of how many are expressed. I think I'm trying 4 3 currently. You need to create your dark frame first using allskeye before the hot pixel bit works on that screen.